Terpene ethers



rsu-med Nov. 13, 1945 TERPENE ETHERS Alfred n Rnmmelsburg, Wilmington, Del., assignor to Hercules Powder Company, Wilmington, Deli, a corporation of Delaware No Drawing. Application June 17, 1948, Serial No. 491,219

13 Claims. (01. 260-611) This invention relates to terpene ethers of unsaturated alcohols and more particularly to the terpene ethers of an unsaturated aliphatic alcohol oi not more than six carbon atoms and to with one part of 95% sulfuric acid and the mixture heated at a temperature of 100 C. for a period of four hours and then cooled to 30 C. The reaction mixture was then passed through a the methodior the production of these terpene water scrubber to remove all water-soluble comethcrs. ponents and then passed through a caustic In accordance with the present invention, it scrubber to neutralize the mixture and then rehas been discovered that terpene ethers may be passed through the water scrubber. The scrubbed made when a terpene compound and anunsatureaction mixture was then fractionated at 20 mm. rated aliphatic alcohol or not more than six .pressure to recover the substantially chemically carbon atoms are caused to be reacted with each pure allyl-isobornyl ether which wasa colorless other under a proper chemical environment. liquid having a unique fragrant odor and having Generally, it has been discovered that a tera refractive index at 20 C. of 1.643 and a specific pene may be caused to be reacted with anunsatugravity of 0.914 at 20 (L/4 C. A yield of 85% rated aliphatic alcohol when the two components terpene ether was obtained. are heated together in the presence of an etheri- Other terpenes were reacted with other allflcation catalyst until etheriflcation is at least phatic alcohols in accordance with the procedure partially complete. set forth in Example 1, using various conditions More particularly, a terpene compound as, for of reaction as shown in the following examples:

Enmplc Tcrpcne ma Alcohol m $3 Tim RE? mm 0 Percent Alpha-plume..-" 600 Ally] an 56-40 'i 95% sulfuric acid so as, Dlpentens 500 (In 500 1160 a an 2 10 mos... too --...do-... 500 so a do mpheno. 500 cm 1-.-. 500 100 4 Bra..-" 10 85 fi :0 a d l 3 5566485 2 2 3M651 500 Mothallyl. 500 100 4 -roiuensrizfiifii'ham 1o 75 I Reaction carried out under pressure. example, the blcyclic terpene, camphene, the as 9 monocyclic terpene, dipentene, or the acyclic ter. pene, myrcene, may be caused to undergo an etheriflcation reaction with an unsaturated aliphatie alcohol as, for example, allyl alcohol, methallyl alcohol, or crotyl alcohol when the two components are heated together at a temperature between about 10 C. and about 200 C. in the presence or a suitable etheriflcation catalyst as. i'or example, sulfuric acid, para-toluene sulfonic acid, and boron trifluoride for a reaction time of about iour hours, the temperature conditions and reaction time depending upon the terpene and alcohol components being used, together with the nature oi the catalyst.

The process involved for the production of terpene ethers in accordance with this invention is illustrated by the following example, the parts being by weight:

Exams: 1

AllyL-Isobm'nyl ether An ether pot was chargedwith 300 parts of camphene and 300 part 01 allyl alcohol together a mixture of 500 parts of sodium fenchylate and 500 parts oi allyl chloride were heated under pressure at 130 C. for 8 hours. The product was recovered by the method described in Example 1. The yield of fenchyl ally] ether was 89%. 4

In accordance with the present invention, the general classes of terpenes found operable are the blcyclic, monocyclic, and acyclic terpenes. Typical bicycllc terpenes found operable are camphene, alpha-pinene, beta-pinene, alpha-fen chene, beta-fenchene, gamma-fenchene, cyclofenchene, tricyclene, aJpha-thujene, beta-thu- Jene, sabinene, S-carene, 4-carene, bornylene. Typical monocyclic terpenes found operable are the paramenthadienes, dipentene, terplnolene, alpha-terpinene, beta-terpinene, gamma-terpinene, alpha-phellandrene, and pyronenes. Typical paramenthenes found operable are carvomenthene. 8-methene, dihydro-terpinolene, dihydrodipentene. Typical acylic terpenes found operable are the acyclic terpenes, myrcene, ocimene,

wvtotaeneae. and allo-ocim as well as dithe presence of an etheriflcation lysts found suitable in accordance with this insix carbon atoms is caused to be reacted with a terpene compound by heating the components in catalyst. Catavention are inorganic acids as, for example, sul- {uric acid, paratoluene sulfonic acid, phosphoric acids, hydrochloric acid,

hydrofluoric acid, boric acid, boron trifluoride. and its organic ether complexes, perchloric acid and fluoboric acid. The catalyst most economical to use will depend upon the conditions under which the reaction is being carried out. Generally, sulfuric acid is preferred operable acyclic terpene alco-' water-washed, and vacuum distilled to separate the ethers.

' acetone or other ketones, ethyl If desired, inert solvents may be present during the preparation of the terpene ethers, by any of the processes herein described. Solvents such as ether, isopropyl ether, petroleum hydrocarbons, aromatic hydrocarbons, chlorinated hydrocarbons, etc., may be employed. Chlorinated h'ydrocrabons are, in general, only used as solvents in cases of the direct reaction of terpenes with the unsaturated alcohols.

The method in accordance with the present invention may be carried out as a batch operabecause of its many advantages including low cost and ease of removal from the products of reac' tion. From 0.1% to may be utilized.

Temperatures of from about 10 C. to about 200 C. may be used in carrying out the etheriflcation reaction between the terpenes and the unsaturated aliphatic alcoh'ols of this invention and 10%- by weight of catalyst when using an acid acting etheriflcation catalyst.

When a terpene of the monocyclic or acyclic class is being etherifled, it is preferred to use temperatures between about 40 C. and about 180' C. The bicycllc terpene, camphene, isreadily etherifled under temperatures between about '70" C. and about 150 C. The pinenes are preferably reacted under temperatures between about C.

and about 50 C. A, closed system. or autoclave is used when the reaction temperature is above the reflux temperature of the reaction mixture.

The time of reaction required to provide at least partial completion of the etheriflcation reaction will vary with the specific reactants used and with the spec fic conditions of contacting and will generally be within the range from about one to about 80 hours. An excess of the unsaturated aliphatic alcohol may, if desired, be employed.

An excess of from about 0.1 mol to about 5 mols more alcohol than the amount of terpene being used may be employed and it is preferred to use about 0.2 mol to about 1 mol more alcohol than the amount of terpene used. 0n the other hand, in some cases an excess of terpene may be employed.

When terpene alcohols are to be etherifled with one of the unsaturated alcohols of the present invention, it is necessary to .form the alkali metal alcoh'olate as,-for example. sodium or potassium fenchylate, terpinylate, or myrcenylate which must then be reacted with the halide of the un saturated alcohol as, for example, allyl chloride,

or bromide. The reaction is desirably carried out in a closed system at about 40 C. to about 150 0., and for a period of from about 1 to about 12 hours. An excess of the halide is usually employed. No catalyst is necessary when an alcoholate is reacted with allyl, methallyl, andcrotyl h'alides. The reaction mixture is then tion, or as a continuous process. The continuous process may comprise an ether pot into which is continuously fed the terpene and alcohol to-be cases the reaction mixture may be directly treated with alkali to neutralize the catalyst, followed by distillation.

Broadly the present invention contemplates the use of unsaturated aliphatic alcohols containing not more than six carbon atoms. These alcohols include the olefinic type,'operable members of which are, for example, allyl alcohol, 2-buten-1- ol (crotyl), propenyl alcohol, iso-propenyl alcohol, 3-buten-l-ol, 3-buten-2-ol, 1-penten-3-ol, i-penten-l-ol, 4-penten-2-ol, 3-penten-2-ol, 2- methyl-4-penten-2-ol, etc. These alcohols also include the acetylenic type, an operable member of which is, for example, 2propyn-1-ol (prepargyl). The terpene ethers produced in accordance with this invention may be represented by means of the following structural formula:

where T is a terpene radical and R is a radical of an unsaturated aliphatic alcohol containing not more than six carbon atoms.

In accordance with the foregoing description, it is aparent that a new composition of matter has been discovered which is a terpene ether of an unsaturated aliphatic alcohol of not more than six carbon atoms, together with the process for its production comprising reacting a terpene compound and an unsaturated aliphatic alcohol togather in the presence of an etheriflcation catalyst and removing the terpene ether from the reaction product.

What I claim and desire to protect by Letters Patent is:

-1. The meth'cd of producing a terpene other which includes reacting a terpene compound with an unsaturated aliphatic alcohol of not more than six carbon atoms in the presence of an acid catalyst at a temperature within the range of about 10 C. and about 200 C'. until etheriflcation is at least partially complete.

2. The method of producing aterpene ether which includes reacting camphene with an unsaturated aliphatic alcohol of not more than six carbon atoms in the presence of sulfuric acid at a temperature within the range of about 70 C. and about C. until etherification is at least partially complete.

3. The method of producing a terpene ether which includes reacting dipentene with an unsaturated aliphatic alcohol or not more than six carbon atoms in the presence of sulfuric acid at a temperature within the range of about 40 C. and about 180 C. until etherification is at least partially complete.

4. The method of producing a terpene ether which includes reacting myrcene with an unsaturated aliphatic alcohol of not more than six carbon atoms in th'e presence of sulfuric acid at a temperature within the range of about 40 C. and about 180 C. until etheriflcation is at least partially complete.

5. An ether having the formula TO-R, in

which '1 is a terpene radical and R is a radical of an unsaturated aliphatic alcohol containing not more than six carbon atoms.

6. An ether having the formula T-O-R, in which T is a bicyclic terpene radical and R is a radical of an unsaturated aliphatic alcohol containing not more than six carbon atoms.

which T is the isobomyl radical and R is a radical of an unsaturated aliphatic alcohol containing not more than six carbon atoms.

9. An ether having the formula T-O-R, in which T is the terpinyl radical and R is a radical of an unsaturated aliphatic alcohol containing not more than six carbon atoms.

10. An ether having the formula T--OR, in which T is the fenchyl radical and R is a radical of an unsaturated aliphatic alcohol containing not more than six carbon atoms.

11. Allyl isobornyl ether.

12. Methallyl terpinyl ether.

13. Allyl fenchyl ether.

ALFRED L, RUMMELSBURG. 

